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Posted to commits@couchdb.apache.org by da...@apache.org on 2017/04/06 16:16:47 UTC
[33/36] couch commit: updated
refs/heads/COUCHDB-3287-pluggable-storage-engines to 0fbcd0c
Ensure deterministic revisions for attachments
This re-fixes a corner case when recreating a document with an
attachment in a single multipart request. Since we don't detect that we
need a new revision until after the document has been serialized we need
to be able to deserialize the body so that we can generate the same
revisions regardless of the contents of the database. If we don't do
this then we end up including information from the position of the
attachment on disk in the revision calculation which can introduce
branches in the revision tree.
I've left this as a separate commit from the pluggable storage engine
work so that its called out clearly for us to revisit.
COUCHDB-3255
Project: http://git-wip-us.apache.org/repos/asf/couchdb-couch/repo
Commit: http://git-wip-us.apache.org/repos/asf/couchdb-couch/commit/4b423871
Tree: http://git-wip-us.apache.org/repos/asf/couchdb-couch/tree/4b423871
Diff: http://git-wip-us.apache.org/repos/asf/couchdb-couch/diff/4b423871
Branch: refs/heads/COUCHDB-3287-pluggable-storage-engines
Commit: 4b4238718c0a2dbf02cc00f6a855ff8ff8d5cd59
Parents: a058366
Author: Paul J. Davis <pa...@gmail.com>
Authored: Wed Feb 8 07:25:37 2017 -0600
Committer: Paul J. Davis <pa...@gmail.com>
Committed: Thu Apr 6 11:15:58 2017 -0500
----------------------------------------------------------------------
src/couch_bt_engine.erl | 10 +++++++++-
src/couch_db.erl | 12 +-----------
src/couch_db_updater.erl | 12 +++++++++++-
3 files changed, 21 insertions(+), 13 deletions(-)
----------------------------------------------------------------------
http://git-wip-us.apache.org/repos/asf/couchdb-couch/blob/4b423871/src/couch_bt_engine.erl
----------------------------------------------------------------------
diff --git a/src/couch_bt_engine.erl b/src/couch_bt_engine.erl
index cf31b09..3b31341 100644
--- a/src/couch_bt_engine.erl
+++ b/src/couch_bt_engine.erl
@@ -324,7 +324,15 @@ serialize_doc(#st{} = St, #doc{} = Doc) ->
SummaryBin = ?term_to_bin({Body, Atts}),
Md5 = couch_crypto:hash(md5, SummaryBin),
Data = couch_file:assemble_file_chunk(SummaryBin, Md5),
- Doc#doc{body = Data}.
+ % TODO: This is a terrible hack to get around the issues
+ % in COUCHDB-3255. We'll need to come back and figure
+ % out a better approach to handling the case when we
+ % need to generate a new revision id after the doc
+ % has been serialized.
+ Doc#doc{
+ body = Data,
+ meta = [{comp_body, Body} | Doc#doc.meta]
+ }.
write_doc_body(St, #doc{} = Doc) ->
http://git-wip-us.apache.org/repos/asf/couchdb-couch/blob/4b423871/src/couch_db.erl
----------------------------------------------------------------------
diff --git a/src/couch_db.erl b/src/couch_db.erl
index 1ba0b90..006c49e 100644
--- a/src/couch_db.erl
+++ b/src/couch_db.erl
@@ -963,7 +963,7 @@ prep_and_validate_replicated_updates(Db, [Bucket|RestBuckets], [OldInfo|RestOldI
-new_revid(#doc{body=Body0, revs={OldStart,OldRevs}, atts=Atts, deleted=Deleted}) ->
+new_revid(#doc{body=Body, revs={OldStart,OldRevs}, atts=Atts, deleted=Deleted}) ->
DigestedAtts = lists:foldl(fun(Att, Acc) ->
[N, T, M] = couch_att:fetch([name, type, md5], Att),
case M == <<>> of
@@ -971,16 +971,6 @@ new_revid(#doc{body=Body0, revs={OldStart,OldRevs}, atts=Atts, deleted=Deleted})
false -> [{N, T, M} | Acc]
end
end, [], Atts),
- Body = case Body0 of
- {summary, [_Len, _Md5, BodyAtts], _SizeInfo, _AttsFd} ->
- {CompBody, _CompAtts} = binary_to_term(BodyAtts),
- couch_compress:decompress(CompBody);
- {summary, [_Len, BodyAtts], _SizeInfo, _AttsFd} ->
- {CompBody, _CompAtts} = binary_to_term(BodyAtts),
- couch_compress:decompress(CompBody);
- Else ->
- Else
- end,
case DigestedAtts of
Atts2 when length(Atts) =/= length(Atts2) ->
% We must have old style non-md5 attachments
http://git-wip-us.apache.org/repos/asf/couchdb-couch/blob/4b423871/src/couch_db_updater.erl
----------------------------------------------------------------------
diff --git a/src/couch_db_updater.erl b/src/couch_db_updater.erl
index d765458..9121a71 100644
--- a/src/couch_db_updater.erl
+++ b/src/couch_db_updater.erl
@@ -520,7 +520,17 @@ merge_rev_tree(OldInfo, NewDoc, Client, Limit, false)
% Update the new doc based on revisions in OldInfo
#doc_info{revs=[WinningRev | _]} = couch_doc:to_doc_info(OldInfo),
#rev_info{rev={OldPos, OldRev}} = WinningRev,
- NewRevId = couch_db:new_revid(NewDoc#doc{revs={OldPos, [OldRev]}}),
+ Body = case couch_util:get_value(comp_body, NewDoc#doc.meta) of
+ CompBody when is_binary(CompBody) ->
+ couch_compress:decompress(CompBody);
+ _ ->
+ NewDoc#doc.body
+ end,
+ RevIdDoc = NewDoc#doc{
+ revs = {OldPos, [OldRev]},
+ body = Body
+ },
+ NewRevId = couch_db:new_revid(RevIdDoc),
NewDoc2 = NewDoc#doc{revs={OldPos + 1, [NewRevId, OldRev]}},
% Merge our modified new doc into the tree